Re: Does anyone have a ROM image from the PET diagnostic pod?

From: Ethan Dicks (
Date: 2008-07-07 11:15:15

On Mon, Jul 7, 2008 at 6:16 AM, William Levak <> wrote:
> On Thu, 3 Jul 2008, wrote:
>> Hallo allemaal,
>> I have two of these boxes. One with a sticker saying "Diagnostic clip
>> series 3000", containing a 2532. Its contents:
> This file contains the same contents twice.  Your EPROM is a 2516 not a
> 2532.  It is also the same as my diagnostic EPROM for the non-6545 PET's.

ISTR a mention of a 2516 (2316?) in the scan of the instructions for the oldest
version of the clip (pre-6545).  Perhaps they changed to a 2532 later
when that's
what they had lying around.  The contents of Ruud's download are, of course
2K of code, duplicated.  I have taken a preliminary pass at it with a
but no more than a glance.  It appears that to make "printing" easy, they emit
strings right to screen memory at pre-calculated fixed X, Y positions - not even
a "print" subroutine in the ROM.

> I have transferred my diagnostic EPROM files to my pc.  There are 3:
>   non-6545 PET's       - 2K
>   40 column 6545 PET's - 4K
>   80 column 6545 PET's - 4K

Nice.  I don't have a CTRC PET with me, but I have more than a few
at home.

> My diagnostic device for the 6545 PET's has a switch that selects between 40
> or 80 columns, and contains both the 6545 EPROM's.  I believe there was an
> older version of this device that had only the 40 column EPROM, and no
> switch.

I may have a 40-col--CTRC-only diagnostic clip at home, but I'm not
sure.  I can't
check it for months.

> I have some instructions that go with these, that I need to transcribe, and
> then I will upload the package to

Thank you for that.

I don't mind drawing up schematics of the innards with something like
EagleCAD, but I don't have a wiring diagram.  Is that something that
you might be able to provide as well?  The docs I just read mentioned
one chip inside besides the ROM, so it shouldn't be too complicated
to describe.


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